Multi-zone air handler and method for using the same

ABSTRACT

A multi-zone air handler and method are provided. The multi-zone air handler comprises a housing, at least one return port in the housing, a first outlet port, a second outlet port, a first blower, a second blower, and at least one air conditioning element. The first outlet port of the housing is for coupling to a first duct. The second outlet port of the housing is for coupling to a second duct. The first blower is positioned in the housing to draw a first airflow from at least one of the at least one return ports, into a first air passage within the housing, and out through the first outlet port. The second blower is positioned in the housing to draw a second airflow from at least one of the at least one return ports, into a second air passage within the housing, and out through the second outlet port. The at least one air conditioning element is disposed in the first air passage and the second air passage for conditioning the first airflow and the second airflow.

TECHNICAL FIELD

The following relates generally to climate control. In particular, the following relates to a multi-zone air handler and method for using the same.

BACKGROUND

Zoned residential HVAC systems are well known. There may be two or more zones that may have different needs because of, for example, the size of the space, the characteristics of the zone (such as heat or cold loss, dampness, etc.), the effort required to transport forced air to the zone being serviced, etc. By segregating an environment into zones, the needs of each zone can be addressed without over-servicing or under-servicing the needs of the other zones. In this manner, environmental air control can be provided in a cost-efficient manner.

One such system 20 is shown in FIG. 1. The system 20 includes an air handler 24. A single motor blower 28 draws ambient air via a return port 32 and propels an air stream upwards through a heating element 36, such as coiled hot water pipes, to heat the air. The heated air stream then exits the air handler 24 through an outlet port 40 and through ducting 44 coupled to the outlet port 40. The ducting 44 divides into a first duct branch 44 a and a second duct branch 44 b and, correspondingly, divides the single air stream into a first air stream 48 a and a second air stream 48 b respectively. The first duct branch 44 a directs the first air stream 48 a to a first zone, and the second duct branch 44 b directs the second air stream 48 b to a second zone.

A first set of dampers 52 a that are controlled by a first electro-mechanical motor 56 a or other suitable controller mechanism are positioned within the first duct branch 44 a. A second set of dampers 52 b that are controlled by a second electro-mechanical motor 56 b are positioned within the second duct branch 44 b. By controlling the relative opening of the first and second sets of dampers 52 a, 52 b, the relative volume rates of the first and second air streams 48 a, 48 b can be controlled.

The dampers and actuators are often external to the furnace, as is the case in the system illustrated in FIG. 1. As will be appreciated, the positions of the dampers within the ducts may make them difficult to access for servicing once installed. In some cases, they are internal to the furnace/fan coil, after the single air stream has exited the motor/blower. Whether internal or external, these dampers with actuators operate independently to partially or fully open to allow air to move through them and into external ducting that leads to at least two locations/zones in the residence.

Such zoned residential HVAC systems, however, are relatively expensive to procure, and install. Further, they are relatively expensive to maintain, as they are subject to relatively frequent failure due to multiple moving parts, and in-field labour is costly.

SUMMARY

In one aspect, there is provided a multi-zone air handler, comprising: a housing, at least one return port in the housing, a first outlet port of the housing for coupling to a first duct, a second outlet port of the housing for coupling to a second duct, a first blower positioned in the housing to draw a first airflow from at least one of the at least one return ports, into a first air passage within the housing, and out through the first outlet port, a second blower positioned in the housing to draw a second airflow from at least one of the at least one return ports, into a second air passage within the housing, and out through the second outlet port, and at least one air conditioning element disposed in the first air passage and the second air passage for conditioning the first airflow and the second airflow.

The multi-zone air handler can further include a first septum disposed within the housing and separating the first air passage from the second air passage within the housing.

The position of the first septum within the housing can be adjustable to adjust the sizes of the first air passage and the second air passage.

The position of the first septum within the housing can be adjustable to adjust the relative sizes of the first air passage and the second air passage.

The first blower can be separately controllable from the second blower. The first blower can be controlled by a first thermostat and the second blower can be controlled by a second thermostat.

The capacity of the first blower can differ from the capacity of the second blower.

The multi-zone air handler can further comprise a third outlet port of the housing for coupling to a third duct, and a third blower positioned in the housing to draw a third airflow from at least one of the at least one return ports, into a third air passage within the housing, and out through the third outlet port, and the at least one air conditioning element can be disposed in the first air passage, the second air passage, and the third air passage for conditioning the first airflow, the second airflow, and the third airflow.

The multi-zone air handler can further comprise a second septum disposed within the housing and separating the second air passage from the third air passage within the housing. The position of the second septum within the housing can be adjustable to adjust the size of the third air passage.

Passive backdraft dampers can be deployed in at least one of the first air passage and the second air passage.

In another aspect, there is provided a multi-zone air handler, comprising a housing, at least one return port in the housing, a first outlet port of the housing for coupling to a first duct, a second outlet port of the housing for coupling to a second duct, a first septum disposed within the housing and separating a first air passage terminating at the first outlet port and a second air passage terminating at the second outlet port, and at least one air conditioning element disposed in the first air passage and the second air passage for conditioning a first airflow through the first air passage and the second airflow through the second air passage.

The position of the first septum within the housing can be adjustable to adjust the sizes of the first air passage and the second air passage.

The position of the first septum within the housing can be adjustable to adjust the relative sizes of the first air passage and the second air passage.

The multi-zone air handler can further comprise a third outlet port of the housing for coupling to a third duct, and a second septum disposed within the housing and separating the second air passage and a third air passage terminating at the third outlet port, and wherein the at least one air conditioning element is disposed in the first air passage, the second air passage, and the third air passage. The position of the second septum within the housing is adjustable to adjust the size of the third air passage.

The multi-zone air handler can further comprise passive backdraft dampers deployed in at least one of the first air passage and the second air passage.

In a further aspect, there is provided a method of installing an air handler, comprising installing an air handler, the air handler comprising a housing, at least one return port in the housing, a first outlet port of the housing for coupling to a first duct, a second outlet port of the housing for coupling to a second duct, a septum disposed within the housing to and separating a first air passage terminating at the first outlet port and a second air passage terminating at the second outlet port, and at least one air conditioning element disposed in the first air passage and the second air passage for conditioning a first airflow through the first air passage and the second airflow through the second air passage, installing a first blower in the housing to draw a first airflow from at least one of the at least one return ports, into the first air passage within the housing, and out through the first outlet port, and installing a second blower in the housing to draw a second airflow from at least one of the at least one return ports, into the second air passage within the housing, and out through the second outlet port.

The method can further comprise adjusting the position of the septum within the housing to adjust the sizes of the first air passage and the second air passage.

The method can further comprise adjusting the position of the septum within the housing to adjust the relative sizes of the first air passage and the second air passage.

These and other aspects are contemplated and described herein. It will be appreciated that the foregoing summary sets out representative aspects of a multi-zone air handler to assist skilled readers in understanding the following detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

A greater understanding of the embodiments will be had with reference to the Figures, in which:

FIG. 1 is a sectional view of a prior art zoned residential HVAC system; and

FIG. 2 is a sectional view of a multi-zone air handler in accordance with an embodiment.

DETAILED DESCRIPTION

For simplicity and clarity of illustration, where considered appropriate, reference numerals may be repeated among the Figures to indicate corresponding or analogous elements. In addition, numerous specific details are set forth in order to provide a thorough understanding of the embodiments described herein. However, it will be understood by those of ordinary skill in the art that the embodiments described herein may be practiced without these specific details. In other instances, well-known methods, procedures and components have not been described in detail so as not to obscure the embodiments described herein. Also, the description is not to be considered as limiting the scope of the embodiments described herein.

Various terms used throughout the present description may be read and understood as follows, unless the context indicates otherwise: “or” as used throughout is inclusive, as though written “and/or”; singular articles and pronouns as used throughout include their plural forms, and vice versa; similarly, gendered pronouns include their counterpart pronouns so that pronouns should not be understood as limiting anything described herein to use, implementation, performance, etc. by a single gender; “exemplary” should be understood as “illustrative” or “exemplifying” and not necessarily as “preferred” over other embodiments. Further definitions for terms may be set out herein; these may apply to prior and subsequent instances of those terms, as will be understood from a reading of the present description.

The following provides a multi-zone air handler and method for using the same. The described air handler comprises a housing having a first blower and a second blower therein, each of which draws a separate airflow into a separate air passage in the housing and out through separate outlet ports coupled to separate ducts. At least one air conditioning element is disposed in the separate air passages to condition the separate airflows. By using two motors for propelling air through separate air passages in the housing, the airflow volume rates for each zone is varied by simply controlling the corresponding blower. Further, actuators and active dampers are not required in order to control the airflow to each zone.

FIG. 2 shows a multi-zone air handler 100 in accordance with an embodiment. The multi-zone air handler 100 has a housing 104 with a return port 108 for permitting the ingress of return air from an environment being conditioned. The return port 108 can be coupled to ducting through which return air is drawn. A first blower 112 a and a second blower 112 b are positioned inside the housing 104 to draw the return air and force it along separate air passages. As used herein, the term “blower” includes any suitable motor-driven fan for use in an air handler. The first blower 112 a and the second blower 112 b are each controlled via separate circuitry, thus enabling their independent operation.

A septum 116 divides the downstream interior portion of the housing 104 into two separate air passages 120 a, 120 b. A first air stream generated by the first blower 112 a is forced through a first air passage 120 a, and a second air stream generated by the second blower 112 b is forced through a second air passage 120 b. As shown, the septum 116 is configured to divide the downstream interior portion of the housing 104 such that the first air passage 120 a is markedly larger than the second air passage 120 b. While a particular configuration of the septum 116 is illustrated, it will be appreciated that other configurations of the septum 116 for dividing the first air passage 120 a from the second air passage 120 b can be provided.

At least one conditioning element 124 is disposed in the first air passage 120 a and the second air passage 120 b. The conditioning element 124 can be a heating element, a cooling element, a humidifying element, a dehumidifying element, etc. For example, in the illustrated embodiment, the conditioning element 124 is a heating coil of hot water pipes from a hot water boiler/heater and through which the air streams to be heated flow.

The first air passage 120 a terminates at a first outlet port 128 a. The first outlet port 128 a is coupled to a first duct 132 a servicing a first zone of an environment. Similarly, the second air passage 120 b terminates at a second outlet port 128 b. The second outlet port 128 b is coupled to a second duct 132 b servicing a second zone of an environment. Thus, the air streams 120 a, 120 b forced out along the first and second ducts 132 a, 132 b respectively are directly controlled by the first and second blowers 112 a, 112 b.

Passive “backdraft dampers” 136 a, 136 b can be employed in order to prevent the backflow of air along one air passage into another air passage when one blower is not active. The backdraft dampers 136 a, 136 b are easily blown out of the way by an airflow generated by the blowers 112 a, 112 b, but effectively stop the backdraft of air into the air handler 100. The backdraft dampers 136 a, 136 b can be made of a flexible material, such as Tedlar™ or mylar, a rigid material such as a thin metal or plastic layer sheet, or a combination of both, such as a lightweight membrane extended over a rigid frame, fixed within the air passages with hinges, living hinges, etc. In some cases, a single backdraft damper, such as backdraft damper 136 a, can be employed to stop the backdraft of air into the other air passage 120 b of the air handler 100, whereas in other cases, two or more backdraft dampers, such as backdraft damper 136 b, can be employed to stop the backdraft of air into the other air passage 120 a. In an alternative embodiment, the backdraft dampers can be a sheet of light gauge metal that straddles a hinge that only opens one way up when air blows up from the blower. When the air stops, it is slightly heavier on one side and it closes. Air coming from the other direction would serve to “push” it closed. Alternatively, the backdraft dampers can be positioned within the housing 104, such as just above the blowers.

As illustrated, the air handler 100 is configured to provide forced air at a maximum volume rate of 150 cubic feet per minute (“CFM”) to the first duct 132 a and forced air at a maximum volume rate of 250 CFM to the second duct 132 b for a total of 400 CFM. Typical residential air handlers generally do not exceed a capacity of 2000 CFM. Various configurations can be provided in other embodiments. For example, an air handler can be provided that provides forced air at a maximum volume rate of 1000 CFM to a first duct and forced air at a maximum volume rate of 600 CFM to a second duct.

Each of the first and second blowers 112 a, 112 b is controlled by separate thermostats for each of the zones being managed. Thus, for example, in a heating mode, if the temperature drops below a specified minimum temperature in a thermostat for a first zone being serviced by the first duct 132 a, then the thermostat directs the first blower 112 a to operate until the minimum temperature is satisfied. Similarly, if the temperature drops below a specified minimum temperature in a thermostat for a second zone being serviced by the second duct 132 b, then that thermostat directs the second blower 112 b to operate until the minimum temperature is satisfied.

In a typical application, the selection of the first and second blowers 112 a, 112 b can be made at the time of installation of the air handler 100. As an example, in an application where the air handler 100 is installed in a residential dwelling having two zones of different sizes, a lower capacity blower can be selected to service the smaller zone and a higher capacity blower can be selected to service the larger zone. The air handler 100 may thus be preconfigured with blowers or the air handler 100 can be provided separate of the blowers.

The septum can be configurable to change the relative sizes of the first air passage and the second air passage. For example, in one embodiment, the septum can mounted within the housing on rails to enable its shifting within the housing, thus modifying the relative sizes of the air passages. In another embodiment, the septum can be hinged to permit its biasing, and securable within the housing once biased at a desirable angle. In addition, the first and second outlet ports can be sized to correspond with the configuration of the septum.

The multi-zone air handler can be installed like any other residential zoned forced air system. A few extra sensors can be installed to control the operation of each motor (on/off/modulate air flow amount to each zone). For example, one or more sensors can measure the temperature of the return air or the outgoing forced air. Occupancy sensors, such as motion or weight sensors, can be placed inside one or more zones to determine what type of conditioning of the air to the zone should be provided, if any.

While, in the above-described embodiment, the air handler is provided with two separate blowers, it will be appreciated that the air handler can be alternatively configured with three or more separate blowers to service three or more separate zones. One or more septums can be provided to divide the air passages from each blower from one another, and separate outlet ports can be provided for ducts extending to each zone. In this scenario, three thermostats can be employed to separately control each of the three blowers and, thus, the airflow provided to each of the three zones. In another embodiment, a single thermostat that has remote thermistors in each zone can be deployed to regulate the temperature in each zone.

While the air handler is described as having a single air conditioning element, it will be appreciated that two or more air conditioning elements can be positioned within the air passages. For example, the air handler can be equipped with a heater coil as well as a humidifier to condition the air passing through.

One or more return ports can be provided to enable return air to enter the air handler. The return ports can be dedicated to serving a particular blower or can be used to enable a pool of air to enter the air handler for drawing by the blowers.

Although the invention has been described with reference to certain specific embodiments, various transformations thereof will be apparent to those skilled in the art. The scope of the claims should not be limited by the preferred embodiments, but should be given the broadest interpretation consistent with the description as a whole. 

1. A multi-zone air handler, comprising: a housing; at least one return port in the housing; a first outlet port of the housing for coupling to a first duct; a second outlet port of the housing for coupling to a second duct; a first blower positioned in the housing to draw a first airflow from at least one of the at least one return ports, into a first air passage within the housing, and out through the first outlet port; a second blower positioned in the housing to draw a second airflow from at least one of the at least one return ports, into a second air passage within the housing, and out through the second outlet port; and at least one air conditioning element disposed in the first air passage and the second air passage for conditioning the first airflow and the second airflow.
 2. The multi-zone air handler of claim 1, further comprising: a first septum disposed within the housing and separating the first air passage from the second air passage within the housing.
 3. The multi-zone air handler of claim 2, wherein the position of the first septum within the housing is adjustable to adjust the sizes of the first air passage and the second air passage.
 4. The multi-zone air handler of claim 2, wherein the position of the first septum within the housing is adjustable to adjust the relative sizes of the first air passage and the second air passage.
 5. The multi-zone air handler of claim 1, wherein the first blower is separately controllable from the second blower.
 6. The multi-zone air handler of claim 5, wherein the first blower is controlled by a first thermostat and wherein the second blower is controlled by a second thermostat.
 7. The multi-zone air handler of claim 1, wherein the capacity of the first blower differs from the capacity of the second blower.
 8. The multi-zone air handler of claim 1, further comprising: a third outlet port of the housing for coupling to a third duct; and a third blower positioned in the housing to draw a third airflow from at least one of the at least one return ports, into a third air passage within the housing, and out through the third outlet port; and wherein the at least one air conditioning element is disposed in the first air passage, the second air passage, and the third air passage for conditioning the first airflow, the second airflow, and the third airflow.
 9. The multi-zone air handler of claim 1, further comprising: a second septum disposed within the housing and separating the second air passage from the third air passage within the housing.
 10. The multi-zone air handler of claim 9, wherein the position of the second septum within the housing is adjustable to adjust the size of the third air passage.
 11. The multi-zone air handler of claim 1, further comprising: passive backdraft dampers deployed in at least one of the first air passage and the second air passage.
 12. A multi-zone air handler, comprising: a housing; at least one return port in the housing; a first outlet port of the housing for coupling to a first duct; a second outlet port of the housing for coupling to a second duct; a first septum disposed within the housing and separating a first air passage terminating at the first outlet port and a second air passage terminating at the second outlet port; and at least one air conditioning element disposed in the first air passage and the second air passage for conditioning a first airflow through the first air passage and the second airflow through the second air passage.
 13. The multi-zone air handler of claim 12, wherein the position of the first septum within the housing is adjustable to adjust the sizes of the first air passage and the second air passage.
 14. The multi-zone air handler of claim 12, wherein the position of the first septum within the housing is adjustable to adjust the relative sizes of the first air passage and the second air passage.
 15. The multi-zone air handler of claim 12, further comprising: a third outlet port of the housing for coupling to a third duct; and a second septum disposed within the housing and separating the second air passage and a third air passage terminating at the third outlet port; and wherein the at least one air conditioning element is disposed in the first air passage, the second air passage, and the third air passage.
 16. The multi-zone air handler of claim 15, wherein the position of the second septum within the housing is adjustable to adjust the size of the third air passage.
 17. The multi-zone air handler of claim 12, further comprising: passive backdraft dampers deployed in at least one of the first air passage and the second air passage.
 18. A method of installing an air handler, comprising: installing an air handler, the air handler comprising: a housing; at least one return port in the housing; a first outlet port of the housing for coupling to a first duct; a second outlet port of the housing for coupling to a second duct; a septum disposed within the housing to and separating a first air passage terminating at the first outlet port and a second air passage terminating at the second outlet port; and at least one air conditioning element disposed in the first air passage and the second air passage for conditioning a first airflow through the first air passage and the second airflow through the second air passage; installing a first blower in the housing to draw a first airflow from at least one of the at least one return ports, into the first air passage within the housing, and out through the first outlet port; and installing a second blower in the housing to draw a second airflow from at least one of the at least one return ports, into the second air passage within the housing, and out through the second outlet port.
 19. The method of claim 18, further comprising: adjusting the position of the septum within the housing to adjust the sizes of the first air passage and the second air passage.
 20. The method of claim 18, further comprising: adjusting the position of the septum within the housing to adjust the relative sizes of the first air passage and the second air passage. 